Tag Archives: environment

What’s that? You’ve never heard of Sgt. Macaque or Dr. Shepherd? Well that’s probably because I just made those names up.

What do you mean “questionable credentials”?

I did so, however, based on two very real headlines that I happened across in the past few weeks. Both are fascinating examples of humans taking advantage of other species’ adaptations to help us meet our goals, and both got me thinking about the prevalence and significance of this kind of human/animal ‘partnership.’

For those of you not inclined to click on the link, I will summarize. The People’s Liberation Army of China (aka the Chinese military) has revealed that a small unit of trained macaque monkeys is being used at one of the country’s Air Force bases to prevent migrating birds from nesting in the area and potentially getting sucked into aircraft engines (an occurrence that is good for neither the bird nor the aircraft/pilot). According to the PLA, the monkeys, which are trained to destroy birds’ nests in response to whistle commands, are proving a more effective deterrent than scarecrows, netting, firecrackers, or human soldiers. Not surprising, given that monkeys have evolved to be more adept at arboreal maneuvering than men of either flesh or straw.

This one is pretty self-explanatory. Researchers in Italy trained two German Shepherds that had previously worked as explosive-sniffing dogs to recognize the scent of volatile organic compounds — chemicals associated with cancerous tumors — in urine samples. In a subsequent blind study of almost 700 men, the dogs correctly identified which urine samples came from men with prostate tumors 98% of the time. This success echoes previous research with medical detection dogs, which has found evidence that dogs can detect lung and breast cancers by smelling a person’s breath, and that they can be trained to warn individuals with diabetes or epilepsy of low blood sugar or impending seizures.

1. Dogs have an amazingly good sense of smell. Their noses contain up to 300 million olfactory receptors (ours have a measly 6 million), and a substantial portion of their brain is devoted to analyzing the smells registered by those receptors. This means that they can smell in parts per trillion. Imagine being able to smell one drop of blood in 20 Olympic swimming pools worth of water (sharks, by contrast, smell in parts per million or billion), and you’ll start to get an idea of how natural selection has honed this adaptation in canines.

Humans, in fact, have created quite a niche for ourselves by exploiting other animals’ abilities. And we’ve been doing it for a long time. Recent evidence suggests that humans have been co-evolving with dogs, the first domesticated animal, for 30,000 years. The domestication of farm and labor animals was more recent but, as evolutionary biologist Jared Diamond has thoroughly explained, it has had an enormous impact on the development of human societies over the past 10,000 years. The truth of the matter is that humans just wouldn’t be where we are today if we didn’t have these conscripts.

But here, I think, is where it is worth making a big distinction between the subjects of the two headlines above. Macaques are not domesticated. Nor are a variety of other species that humans have put into service more recently, such as military marine mammals. And this raises some major ethical dilemmas. Is it okay for humans to use animals in this way? For decades, the US Navy has taken advantage of dolphins’ swimming and echolocation abilities to detect and clear mines (good for the human population), but military sonar has simultaneously contributed to making the ocean a more unhealthyenvironment (bad for marine wildlife). How much of a qualitative difference is there between this and the efforts of an organization like Helping Hands, which trains capuchin monkeys to act as service animals to the severely disabled? Under what circumstances, if any, does human need trump an animal’s (or species’) right to live undisturbed in its natural habitat? Do the “rules” differ for domesticated vs. non-domesticated species? As someone who has admitted to having a Grand Canyon-sized soft spot for animals, these are questions that I genuinely don’t have answers for, and I am curious to hear other people’s thoughts.

In the meantime, I will finish with one more current news story, this time about a handful of humans doing something to help out animals:

Medical Detection Dogs and the In Situ Foundation are but two of myriad organizations devoted to training dogs to use their noses in service of human health. Read this essay, however, for an alternative perspective on the use of dogs in medical detection.

I recently finished reading Alan Weisman’s 2007 book The World Without Us, an extended thought experiment about what would happen on Earth if humans were suddenly to vanish tomorrow, and I am unsettled. My emotional mind and my academic mind are in conflict, battling one another over what to take away from the book. It’s like a series of dominance displays in my brain.

Ok, that might be a bit of an exaggeration. But I am having difficulty settling on a perspective.

On the one hand, each of Weisman’s chapters emphasizes a way in which humans, through our industrial and technological innovations, will leave a legacy of environmental degradation (or at least change) that can be expected to last thousands, tens of thousands, or millions of years. By imposing our will on the natural world, we not only have carved out a niche for ourselves; we have simultaneously altered the habitats of other organisms in ways most people don’t even realize. How many people, when they take their groceries home in plastic bags, stop to think about the fact that these bags may end up in one of the floating garbage patches that are slowly expanding across oceans and affecting marine wildlife? Do you or anyone you know ever consider, as you laugh at Homer Simpson’s antics in the nuclear power plant, the problems inherent in storing tons of radioactive waste or how that waste would affect surrounding soils if its containers began to erode? Out of every 10 cell phone calls you make, after how many do you pause to reflect on the millions of birds that are killed each year by communication towers?

My emotional mind weeps at these thoughts. It mourns the species we are rapidly driving to extinction, and it worries about how humans’ continually increasing population size and demand for resources will affect our own future. Reading this book, the magnitude of our impact on our surroundings frequently left the conservationist in me feeling panicked and hopeless.

And yet, on the other hand, Weisman reminds us that the earth’s habitats and organisms have weathered disaster before, and that given enough time, even Homo sapiens’ most durable creations and byproducts will eventually be diluted and recycled by natural processes. We may leave the planet in an altered state — with higher atmospheric levels of carbon dioxide, more radioactive soils, and widely distributed toxic dioxins — but we are unlikely to leave it barren. Life, via evolution, will ultimately find a way. This too shall pass.

My academic mind, playing the role of the optimist, wants to focus on this long-term perspective. After all, as an anthropologist I am used to talking about vast swaths of time: Homo sapiens first evolved around 200,000 years ago, humans and chimpanzees last shared a common ancestor approximately 6 to 8 million years ago, primates first appear in the fossil record close to 60 million years ago, etc. Even if the planet takes hundreds of millions of years to “recover” from our activities, isn’t that just a drop in the bucket compared to the 4.5 billion years it has already been around? Put another way, if in the past 250 million years biodiversity was able to rebound from the Permian-Triassic extinction, which wiped out around 95% of all marine species and 70% of terrestrial vertebrates, will the impact of humans’ actions on the environment really be that significant?

As cliched as it sounds, only time will tell. In the meantime, given the unlikelihood of our species simply disappearing, I would be interested to know how Weisman and his collaborators picture a future in which the human species continues to grow (Weisman’s suggestion that we try to scale back our imprint by voluntarily adopting a ‘one child per woman’ policy, though coldly logical, is highly unlikely) and play out its existence through more realistic, possibly even radical, means.